Rucio is a software framework that provides functionality to organize, manage, and access large volumes of scientific data using customizable policies. Versions prior to 35.8.3, 38.5.4, and 39.3.1 have a stored Cross-Site Scripting (XSS) vulnerability in the Custom Rules function of the WebUI where attacker-controlled input is persisted by the backend and later rendered in the WebUI without proper output encoding. This allows arbitrary JavaScript execution in the context of the WebUI for users who view affected pages, potentially enabling session token theft or unauthorized actions. Versions 35.8.3, 38.5.4, and 39.3.1 fix the issue.

Affected: PyPI: rucio-webui

### Summary A stored Cross-site Scripting (XSS) vulnerability was identified in the Custom Rules function of the WebUI where attacker-controlled input is persisted by the backend and later rendered in the WebUI without proper output encoding. This allows arbitrary JavaScript execution in the context of the WebUI for users who view affected pages, potentially enabling session token theft or unauthorized actions.

--- ### Details A malicious payload supplied in the `comment` field is stored by the backend. When the rule is later viewed or approved, the stored script executes in the WebUI origin.

**Create Path**: Monitoring > Subscriptions and Rules > Request New Rule > Options > Add Comment

**Trigger Paths**: - **User Trigger**: Monitoring > Subscriptions and Rules > Show My Rules > *RULE NAME* (`https://localhost:8443/ui/rule?rule_id=<RULE_ID>`) - **Admin Trigger**: Data Transfer (R2D2) > Approve Rules > *RULE NAME*

**Create Request** ```http POST /proxy/rules/ HTTP/1.1 ... {"dids":[{"scope":"test","name":"dataset1"}],"account":"pentest","ask_approval":true,"activity":"User Subscriptions","rse_expression":"WEB1","copies":1,"grouping":"DATASET","lifetime":15552000,"comment":"<script>alert(document.cookie)</script>","asynchronous":false,"notify":"N"} ```

**Response** ```http HTTP/1.1 201 CREATED ... ["c2d675c1979d4549b26eede3531a7e6a"] ```

**Creating RSE with XSS payload in comment** <img width="1032" height="667" alt="Creating RSE with XSS payload in comment" src=…

Affected: PyPI: rucio-webui

### Summary A stored Cross-site Scripting (XSS) vulnerability was identified in the Custom Rules function of the WebUI where attacker-controlled input is persisted by the backend and later rendered in the WebUI without proper output encoding. This allows arbitrary JavaScript execution in the context of the WebUI for users who view affected pages, potentially enabling session token theft or unauthorized actions.

--- ### Details A malicious payload supplied in the `comment` field is stored by the backend. When the rule is later viewed or approved, the stored script executes in the WebUI origin.

**Create Path**: Monitoring > Subscriptions and Rules > Request New Rule > Options > Add Comment

**Trigger Paths**: - **User Trigger**: Monitoring > Subscriptions and Rules > Show My Rules > *RULE NAME* (`https://localhost:8443/ui/rule?rule_id=<RULE_ID>`) - **Admin Trigger**: Data Transfer (R2D2) > Approve Rules > *RULE NAME*

**Create Request** ```http POST /proxy/rules/ HTTP/1.1 ... {"dids":[{"scope":"test","name":"dataset1"}],"account":"pentest","ask_approval":true,"activity":"User Subscriptions","rse_expression":"WEB1","copies":1,"grouping":"DATASET","lifetime":15552000,"comment":"<script>alert(document.cookie)</script>","asynchronous":false,"notify":"N"} ```

**Response** ```http HTTP/1.1 201 CREATED ... ["c2d675c1979d4549b26eede3531a7e6a"] ```

**Creating RSE with XSS payload in comment** <img width="1032" height="667" alt="Creating RSE with XSS payload in comment" src=…